1. Field of the Invention
The present general inventive concept relates to an image forming apparatus and a method to operatively control the same, and more particularly, to an array type image forming apparatus having a plurality of print heads arranged in a widthwise direction of a print medium, such as a paper, and a method for operatively controlling the same.
2. Description of the Related Art
In general, an image forming apparatus, such as an ink-jet printer, ejects fine droplets of inks to desired positions on a print medium, such as a paper or a cloth, so as to print a predetermined color image on a surface of the print medium. A conventional ink-jet printer includes an ink cartridge for printing an image while reciprocating in a direction at a right angle to a print medium feeding direction, i.e., in a widthwise direction of the print medium. However, such a conventional ink-jet printer with an ink cartridge for printing an image while reciprocating has a disadvantage in that a printing speed is very slow.
Recently, ink-jet printers have been developed to employ an ink cartridge having a plurality of print heads arranged over the entire width of a print medium, so that an image can be rapidly printed without reciprocating the ink cartridge. Such ink-jet printers are also referred to as array print head type ink-jet printers.
A conventional array print head type ink cartridge includes a plurality of ink tanks, each for storing a print ink, a plurality of negative pressure adjustment units connected to the ink tanks, respectively, a plurality of print heads arranged in a predetermined pattern in the widthwise direction of a print medium, and a ink channel unit for supplying inks from the ink tanks to the print heads.
The ink tanks are mounted on a frame and contain various colors of inks, e.g., yellow (Y), magenta (M), cyan (C) and black (B) inks, respectively.
The negative pressure adjustment units are mounted on the underside of the frame and communicated with the ink tanks, respectively. Such negative pressure adjustment units produce negative pressure so as to prevent the leakage of ink.
The ink channel unit is connected with the negative pressure adjustment units and serves to supply inks admitted from the ink tanks through the negative pressure adjustment units to each of the print heads.
The print heads are arranged in a predetermined pattern on and attached to the front face of the ink channel unit. Each of the print heads is formed with a plurality of nozzles, through which inks supplied from the ink channel unit is ejected onto a print medium, whereby an image is printed on the print medium. In particular, the nozzles are divided according to colors. Typically, the color-specific nozzles are sequentially arranged in the print medium feeding direction.
The above-mentioned array print head type image forming apparatus is advantageous in that the output speed is increased and the construction is simplified. However, such an array print head type image forming apparatus has various problems as follows.
In order to wipe the print heads arranged in the widthwise direction, it is necessary to move a blade in the widthwise direction of a print medium or in the print medium feeding direction, so that the blade wipes the print heads. If a blade is arranged to wipe the print heads while moving in the widthwise direction, a large amount of ink is attached to the blade while wiping the print heads because the blade employed in this type has a small area. Therefore, the blade is not capable of performing a normal wiping operation for a long period, and the length of time required for wiping is very long.
For this reason, there has been proposed to arrange an elongated blade in the widthwise direction of a print medium and to move the elongated blade in the print medium feeding direction, thereby wiping the print heads. However, if the print heads are wiped in this manner, inks are pushed into color-specific nozzles sequentially arranged in the print medium feeding direction, thereby causing color-mixing in the nozzles, which causes a problem in maintenance of a printed image.
Therefore, what is needed is a method which can quickly and cleanly wipe the print heads and solve or at least alleviate the problem of color-mixing.